The process for binding the R617FS receiver is:
Power on the transmitter.
Hold the little button while connecting power to the receiver.
After powering on the RX continue to hold the button and count to ten slowly.
The RX status light should change to solid green after releasing the button. This indicates the RX is bound to the TX.
If other transmitters are in use it is possible to bind the RX to the wrong TX. Move to an area without other TXs.